000 AXPZ20 KNHC 042108 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2108 UTC Thu Jul 4 2019 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Hurricane Barbara centered near 16.7N 130.8W at 04/2100 UTC moving NW at 10 kt. Estimated minimum central pressure is 971 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. A west-northwest to northwest motion is anticipated during the next day or so, followed by a turn toward the west on Saturday. Rapid weakening is forecast, and Barbara is expected to weaken to a tropical storm on Friday and become a post-tropical cyclone on Saturday. See NHC Forecast/Advisory under AWIPS/WMO Headers MIATCMEP2/WTPZ22 KNHC for more details or at website https://www.nhc.noaa.gov/text/MIATCMEP2.shtml for additional details. Showers and thunderstorms continue to show some signs of organization in association with a tropical wave located several hundred miles south-southwest of the coast of southwestern Mexico. Environmental conditions appear conducive for further development, and a tropical depression is likely to form this weekend. This disturbance is expected to move west-northwestward at about 15 mph well off the coast of Mexico. Please see the latest eastern North Pacific tropical weather outlook for more information. ...TROPICAL WAVES... The axis of a tropical wave is near 86W. Scattered moderate convection is noted from 07N to 10N between 85W and 88W. The axis of a tropical wave is near 96W, moving W around 10 kt. Scattered moderate and isolated strong convection is noted from 06N to 10N between 95W and 98W. The axis of a tropical wave is near 105W, moving W around 15 kt. Low pressure 1008 mb has developed along the wave axis near 11N105W. Numerous moderate and scattered strong convection is noted within 60 nm of a line from 13N101W to 14N104W to 12N108W. Scattered moderate and isolated strong convection is noted from 07N to 09N between 102W and 107W. The axis of a tropical wave is near 115W, moving W around 10 kt. This wave is embedded in an area of scattered moderate convection from 04N to 12N between 108W and 118W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 08N78W to 09N86W to 1008 mb low pressure near 11N105W to 10N110W to 12N120W, then resumes from 10N131W to beyond 07N140W. Scattered moderate and isolated strong convection is noted within 120 nm south of the monsoon trough east of 80W, within 120 nm south of the monsoon trough between 88W and 93W, and within 120 nm south of the monsoon trough west of 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a persistent high pressure ridge to the northwest of Baja California and a low pressure trough along the Gulf of California is maintaining moderate to locally fresh NW to N winds off the coast of Baja California. Recent altimeter data off the coast of Baja California Sur showed 7-8 ft seas over the offshore waters, likely in southerly swell from distant Hurricane Barbara. This long period swell will begin to decay tonight as Barbara continues moving NW away from the region. Gulf of California: Gentle to moderate winds will prevail over the northern and central Gulf of California for the next couple days, with mainly gentle winds over the southern Gulf. Southwest gap winds may pulse to fresh speeds over the northern Gulf Sun night and Mon night. Gulf of Tehuantepec: Moderate to fresh nocturnal pulsing of northerly gap winds will begin tonight and continue through the upcoming weekend. Wind speeds are expected to diminish over the Gulf early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong offshore winds will prevail across the Gulf of Papagayo through Sat, then remain fresh into early next week. Elsewhere, gentle to moderate offshore winds will prevail north of the monsoon trough, while gentle to moderate S to SW winds are expected south of the monsoon trough for the next few days. Looking ahead, winds may strengthen to fresh speeds south of the monsoon trough early next week. A set of long period S to SW swell will move into the waters between Ecuador and the Galapagos Islands this weekend with seas building to 8 ft. REMAINDER OF THE AREA... Please see the special features section for more information on Hurricane Barbara. Please see the special features section for more information on the potential for tropical cyclogenesis well southwest of the southern coast of Mexico. The pressure gradient between high pressure north of the area and Hurricane Barbara is supporting moderate to fresh winds over forecast waters north of 20N based on recent partial scatterometer data. Swell generated by Hurricane Barbara is producing seas of 8 ft or greater over much of the forecast waters west of 120W based on available altimeter passes from this afternoon. Cross- equatorial SE to SW swell will prevail for the next several days across the waters generally south of 05N and west of 100W with seas of 7-10 ft. Wave heights will subside by Sun as swell decays over the southern waters. $$ Reinhart